HIV-1 is the causative agent of AIDS. To date there are no promising vaccines or drugs to combat HIV-1. Our approach to the AIDS problem is to use peptide chemistry to develop potential vaccine candidates and new drugs. The work is based on the fact that CD-4 is the cellular receptor for the virus and that the amino acid sequence of CD-4 is well-known. In addition, we are relying on published data to guide us in determining the ligand for CD-4 on the virus. Our goal is to design and synthesize reagents that are capable of blocking the binding of the virus to cells. Anti-viral drugs will be conjugated to these reagents and the conjugates will be tested to evaluate their in vitro efficacy. The primary focus of our work is to develop a "guided missile" anti HIV- 1 reagent. Such a reagent should be able to recognize the receptor for the virus, bind to the receptor and enter the cell through the receptor. In addition, our goal is to not damage the cell but to kill the virus. We are currently developing monoclonal antibodies directed against CD-4, the HIV-1 receptor. Antibodies are against peptides derived from the receptor and should react with the native receptor protein. This makes them unique from what is commercially available. Studies are currently underway to evaluate which anti CD-4 monoclonals are taken up by CD-4 expressing cells. The techniques involved include peptide synthesis, receptor isolation and characterization, amino acid analyses, high performance liquid chromatography, affinity chromatography, new methods of conjugating nucleic acids to antibodies, antibody development and all the associative methods involved in production of specific monoclonals. Cell culture is used to produce large amounts of cells bearing the CD-4 receptor for use in our studies.